Dynamo-electric machine



Oct. 16,1923. 1 1,471,067

H. K. SANDELL DYNAMO ELECTRIC MACHINE Original Filed m. 8', 1917 2sheets shaet 1 Patented Oct. 16, 1923.

UNITED STATES 1,411,0 1 PATENT OFFICE. I

' HENRY K. SANDELL, or CHICAGO, ILLINOIS, ASSIGNO'R TO HERBERT s MILLS,or

' CHICAGO, ILLINOIS.

DYNAMIC-ELECTRIC MACHINE.

Original application filed August 8, 1917, Serial No. 185,009. Dividedand this application filed February 12, 1919. Serial No. 276,565. 1

To all whom it may concern Be it known that I, HENRY K. SANDELL, acitizen of the United States, residing at 221 South Green Street,Chicago, in the I The objects of my invention are to im prove theconstruction of dynamo electric machinery, more particularly that of themotor-generator type; to provide a machine having a single armature withindependent alternating current and direct current windings and anadditional alternating current starting winding; and to provide a,single- I armature combined synchronous singlephase motor and directcurrent generator. Other objects and advantages will be evident uponreading the present specification in connection with the drawingaccompanyin the same.

My invention is illustrated in its preferred embodiment as a selfcontained motor-generator or dynamotor in the accompanying drawings, inwhich- Fig. 1 is a side elevation of a dynamotor or self contained motorgenerator constructed in accordance with my invention.

75 Fig. 2 is an end view thereof, the casing being removed. I

Fig. 3 is the diagram illustrating the wiring of the dynamotor.

In the embodiment of my invention illustrated in the drawings, thedevice operates as a synchronous motor on a single phase current andgenerates a direct current. It com rises a casing or housing 10, whichcarrles or supports a. stator 11. This stator I prefer to construct inaccordance with the method described in my prior application, Serial No.185,009, filed August8th, 1917. of which this application is a division.The

stator constructed in accordance therewith may be laminated 1ncharacter, as shown in the present application, and has an even number.of pole-teeth arranged in four identical groups, the individualpole-teeth in consist of a number, for example 5, of normal pole-teeth12, a pole-tooth 13 at one end wider than the normal pole-teeth, a

pole-tooth 14 adjacent thereto and narrower than the normal pole-teeth,and at the other end of each group a pole-tooth 15, also narrower thanthe normal pole-teeth. The group of poles and the synchronousfield-winding may be relatively'arranged as shown in Fig. 2, there beinga wide slot 16 adapted to receive two windings out side an endpole-tooth 15 of each of the four groups and a narrow slot 17 adapted toreceive one winding between an end poletooth 14 of each group and theadjacent pole-tooth 13. Four windingslS are arranged in these slot-s. Inthe device illus trated there are thirty two individually un symmetricalpole-teeth which are arranged in four symmetrical groups. There are alsofour unsymmetrically arranged synchronous field-windings. As describedin my previous application, this arrangement of poles produces acondition which is not in balance and as a result of which, upon beingenergized the device may be started as an induction motor. Furthermore,by reason of the unsymmetrical arrangemcnt of the synchronousfield-winding, hunting is to a. considerable extent prevented,

I may also provide the stator of my device with a laminated copper grid19, the cross pieces of which extend between the pole-teeth of thestator.

In the embodiment illustrated this grid is similar to the so-calledsquirrel-cage winding in appearance although other i orms may beemployed if desired. In the embodiment of'my invention illustrated, therotor or armature is wound as shown in Fig. 2 and in the wiring diagramof Fig. 3. The armature 20, having an even number of pole-teeth, shownin the drawings as 48, carries three distinct windings. Of these, one isan A. C. running winding, the second is a I). C. generator winding andthe third is'a split-phase A. C. starting winding. The running -winding21 lies nearest the center of the rotor or armature and is arranged toproduce four poles being of the concentric type. Immediately above theA. C. running winding 21 is the DV C. generator Winding Outside of theD. C. geneu ator winding and therefore substantially at the outerperiphery of the armature is the A. C. split-phase starting winding 2The A. C. running winding 21 is connected in the usual manner withslip-rings 2%, the splitphase winding 23 being also ronneeted with theslip-rings thri'iugh a centrifugally operated cut-out switch The C.generator winding is connected with a .COI'IIIHUfiRtOI'QG, from thebrushes oi? which the D, C. service line as well as the field winding 18are energized. The form arrangement of the various windings de scribedis found to he paricularl adar' tageons. The split-phase windings i Hupon the surface oi the armature g1 c a high starting torque and.inter't 'fe with the arrangement of the running windings to thesmallest extent. The A. f. f vindingzs are advantageousiji placed withinthe D. C. lap windings. ti s arra gement giving the maximum ei'hrienc ifitll the minimum structural complication.

In the construction shown, the i), (l. brushes are held in position bysuitable brush-holders 27. The D. C. service iinri indicated as 28 andthe A. C. service line as 29.

lVhile I have shown and described in consiiilerable detail one specificembodiment of my invention, it will he understood that this is for thepurpose of illustration only and to render the invention more clear; andfurthermore that I do not regard the invention as limited to thesedetails nor to an of them except in so far as such limitations areincluded within the terms of the accompanying claim.

llhat I claim as new and desire to secure by Letters Patent, is:

A. dvnamotor having a field, magnet and an armature, a. direct currentwinding on said magnet; an inductively excited winding also arranged onsaid magnet; a winding on the armature, arranged to n'ovide armaturepoles whose angular spacing corresponds to that of the iield poles; asecond winding of an ordinary direct current type also dis posed on saidarmature; and a third winding also'disposed on said armature, said thirdwindii'ip heing arranged to provide armature poles whose angular spacingvorresponds to that of the field poles. but an- .larly displaced fromthe poles p1'o'-.'i-1led by the first mentioned winding. said thirdwinding being disposed near the periphery oi the ariziature, means forsupplying single phase alternating current to the first and thirdwindings and means to cut out the third winding on attainment of a desred rate of rotation.

HENRY K. SANDELL.

